Microwave oven



FIG. 1 is a front perspective view of a microwave oven showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a right side elevational view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a bottom plan view thereof; and

FIG. 6 is a bottom plan view thereof.

The broken lines shown in FIGS. 1, 2, 5 & 6 are for illustrative purpose only and forms no part of the claimed design. 

The ornamental design for a microwave oven, as shown and described. 